Precedence of Properties

The search order for properties is:

1. System-wide properties set programmatically (as a command-line option to the JVM when starting the application or within application code)
2. Database-wide properties
3. System-wide properties set in the derby.properties file

This means, for example, that system-wide properties set programmatically override database-wide properties and system-wide properties set in the derby.properties file, and that database-wide properties override system-wide properties set in the derby.properties file.

There is one important exception to the search order for properties described above: When you set the derby.database.propertiesOnly property to true, database-wide properties cannot be overridden by system-wide properties.

This property ensures that a database's environment cannot be modified by the environment in which it is booted. Any application running in an embedded environment can set this property to true for security reasons.